* {
  padding: 0;
  margin: 0;
  list-style: none;
  user-select: none;
}
.box {
  margin: 50px auto;
  width: 500px;
  height: 300px;
}
.box > .img_box {
  position: relative;
  height: 150px;
  border: 1px solid skyblue;
  background-color: rgba(0, 0, 0, 0.4);
}

.box > .img_box > ul > li {
  position: absolute;
  top: 0;
  left: 0;
  width: 400px;
  transition: all 1s cubic-bezier(0.075, 0.82, 0.165, 1);
}

.box > .img_box > ul > li > img {
  border-radius: 10px;
  width: 100%;
}
.box > .img_box > ul > .img1 {
  transform: translate(0px) scale(0.8);
  transform-origin: left center;
  z-index: 1;
}
/* 第二张不需要缩放 */
.box > .img_box > ul > .img2 {
  /* 
    图片偏移：（500-400）/2=50
     */
  transform: translate(50px) scale(1);
  z-index: 2;
}
.box > .img_box > ul > .img3 {
  /* 
    图片缩放之后的宽度：400*0.8=320
    图片偏移：500-图片缩放的宽度=180
     */
  transform: translate(180px) scale(0.8);
  transform-origin: left center;
  z-index: 1;
}
.box > .img_box > ul > .img4 {
  transform: translate(90px) scale(0.8);
}

/* 左右箭头 */
.arrow_left,
.arrow_right {
  font-size: 20px;
  color: lightcyan;
  margin-top: 10%;
  text-align: center;
  line-height: 40px;
  position: absolute;
  z-index: 999;
  width: 25px;
  height: 40px;
  background-color:lightgray;
}

.arrow_left:hover,
.arrow_right:hover{
  background-color: black;
}

.arrow_right {
  right: 0;
}

.dot_box {
  position: absolute;
  bottom: -40px;
  left: 35%;
  display: flex;
  align-items: flex-end;
  justify-content: space-around;
}

.dot_box span {
  margin-left: 20px;
  width: 20px;
  height: 20px;
  background-color: lightblue;
  display: block;
  border-radius: 50%;
}

.dot_box .active{
  background-color: rgb(120, 224, 189);
}
